Effectiveness of longstanding exercise therapy compared with usual care for people with rheumatoid arthritis and severe functional limitations: a randomised controlled trial.

OBJECTIVES: To compare the effectiveness of longstanding (>52 weeks), supervised exercise therapy with usual care in adults with rheumatoid arthritis (RA) and severe functional limitations. METHODS: Participants were randomised 1:1 to the intervention (individualised goal-setting, active exercises, education and self-management regarding physical activity) or usual care. Primary endpoint was the change in the Patient-Specific Complaints activity ranked 1 (PSC1, 0-10) at 52 weeks. Secondary endpoints included the PSC activities ranked 2 and 3 (PSC2, PSC3), Health Assessment Questionnaire-Disability Index (HAQ-DI), Rheumatoid Arthritis Quality of Life Questionnaire (RAQoL), 6-minute walk test (6MWT), Patient Reported Outcome Measurement Information System Physical Function-10 (PROMIS PF-10) and the Short Form-36 Physical and Mental Component Summary Scales (SF-36 PCS and MCS). (Serious) Adverse events (AEs) were recorded. Measurements were done by blinded assessors. Analyses at 52 weeks were based on the intention-to-treat principle. RESULTS: In total, 217 people (90% female, age 58.8 (SD 12.9) years) were randomised (n=104 intervention, n=98 usual care available for analyses). At 52 weeks, the improvement of the PSC1 was significantly larger in the intervention group (mean difference (95% CI) -1.7 (-2.4, -1.0)). Except for the SF-36 MCS, all secondary outcomes showed significantly greater improvements favouring the intervention (PSC2 -1.8 (-2.4, -1.1), PSC3 -1.7 (-2.4, -1.0), PROMIS PF-10 +3.09 (1.80, 4.38), HAQ-DI -0.17 (-0.29, -0.06), RAQoL -2.03 (-3.39, -0.69), SF-36 PCS +3.83 (1.49, 6.17) and 6MWT +56 (38, 75) m). One mild, transient AE occurred in the intervention group. CONCLUSION: Longstanding, supervised exercise therapy was more effective than usual care in people with RA and severe functional limitations. TRIAL REGISTRATION NUMBER: Netherlands Trial Register (NL8235), included in the International Clinical Trial Registry Platform (https://trialsearch.who.int/Trial2.aspx?TrialID=NL8235).

One-year effectiveness of long-term exercise therapy in people with axial spondyloarthritis and severe functional limitations.

OBJECTIVE: To evaluate the effectiveness of long-term, personalized, supervised exercise therapy on functional ability compared with usual care in people with axial spondyloarthritis (axSpA) and severe functional limitations. METHODS: Participants were randomly 1:1 assigned to the intervention(maximal 64 sessions, with 14 additional optional sessions of supervised active exercise therapy(e.g. aerobic and muscle strengthening) with individualized goal-setting, education and self-management regarding physical activity) or usual care(care determined by clinician(s) and participants themselves). Primary end point was the change in the Patient-Specific Complaints activity ranked 1 (PSC1 (0-10)) at 52 weeks. Secondary endpoints were the PSC activities ranked 2 and 3, the Bath Ankylosing Spondylitis Functional Index, 6-min walk test, Patient Reported Outcome Measurement Information System-Physical Function-10 and the Short Form-36 Physical and Mental Component Summary Score (SF-36 PCS and MCS). Statistical comparisons comprised independent student t-tests and linear mixed models, based on intention-to-treat. RESULTS: 214 participants(49% female, age 52 (SD 12) years), were randomized to the intervention (n = 110) or usual care (N = 104) group. In the intervention group 93% started treatment, using on average 40.5 sessions (SD 15.1). At 52 weeks, the difference in change in PSC1 between groups favored the intervention group (mean difference [95% CI]; -1.8 [-2.4 to -1.2]). additionally, all secondary outcomes, except the SF-36 MSC, showed significantly greater improvements in the intervention group with effect sizes ranging from 0.4-0.7. CONCLUSION: Long-term, supervised exercise therapy proved more effective than usual care in improving functional disability and physical quality of life in people with axSpA and severe functional limitations. CLINICAL TRIAL REGISTER NUMBER: Netherlands Trial Register NL8238, included in the International Clinical Trial Registry Platform (ICTRP) (https://trialsearch.who.int/Trial2.aspx?TrialID=NL8238).

Suitability of the animated activity questionnaire for use as computer adaptive test: establishing the AAQ-CAT.

PURPOSE: The animated activity questionnaire (AAQ) is a computer-based measure of activity limitations. To answer a question, patients choose the animation of a person performing an activity that matches their own level of limitation. The AAQ has not yet been tested for suitability to be applied as computer-adaptive test (CAT). Thus, the objective of this study was to develop and evaluate an AAQ-based CAT to facilitate the application of the AAQ in daily clinical care. METHODS: Patients (n = 1408) with hip/knee osteoarthritis from Brazil, Denmark, France, The Netherlands, Norway, Spain, and the UK responded to all 17 AAQ items. Assumptions of item-response theory (IRT) modelling were investigated. To establish item parameters for the CAT, a graded response model was estimated. To evaluate the performance of post-hoc simulated AAQ-based CATs, precision, test length, and construct validity (correlations with well-established measures of activity limitations) were evaluated. RESULTS: Unidimensionality (CFI = 0.95), measurement invariance (R2-change < 2%), and IRT item fit (S-X2 p > .003) of the AAQ were supported. Performing simulated CATs, the mean test length was more than halved (≤ 8 items), while the range of precise measurement (standard error ≤ 0.3) was comparable to the full AAQ. The correlations between original AAQ scores and three AAQ-CAT versions were ≥ 0.95. Correlations of AAQ-CAT scores with patient-reported and performance measures of activity limitations were ≥ 0.60. CONCLUSION: The almost non-verbal AAQ-CAT is an innovative and efficient tool in patients with hip/knee osteoarthritis from various countries, measuring activity limitations with lower respondent burden, but similar precision and construct validity compared to the full AAQ.

Comparison of physical activity among different subsets of patients with knee or hip osteoarthritis and the general population.

To compare the amount of physical activity (PA) among patients with different subsets of knee or hip osteoarthritis (OA) and the general population. Secondary analyses of data of subjects ≥ 50 years from four studies: a study on the effectiveness of an educational program for OA patients in primary care (n = 110), a RCT on the effectiveness of a multidisciplinary self-management program for patients with generalized OA in secondary care (n = 131), a survey among patients who underwent total joint arthroplasty (TJA) for end-stage OA (n = 510), and a survey among the general population in the Netherlands (n = 3374). The Short QUestionnaire to ASssess Health-enhancing physical activity (SQUASH) was used to assess PA in all 4 studies. Differences in PA were analysed by multivariable linear regression analyses, adjusted for age, body mass index and sex. In all groups, at least one-third of total time spent on PA was of at least moderate-intensity. Unadjusted mean duration (hours/week) of at least moderate-intensity PA was 15.3, 12.3, 18.1 and 17.8 for patients in primary, secondary care, post TJA, and the general population, respectively. Adjusted analyses showed that patients post TJA spent 5.6 h [95% CI: 1.5; 9.7] more time on PA of at least moderate-intensity than patients in secondary care. The reported amount of PA of at least moderate-intensity was high in different subsets of OA and the general population. Regarding the amount of PA in patients with different subsets of OA, there was a substantial difference between patients in secondary care and post TJA patients.

Rationale and design of the PaTIO study: PhysiotherApeutic Treat-to-target Intervention after Orthopaedic surgery.

BACKGROUND: Physiotherapy is a proven effective treatment strategy after total knee and hip arthroplasty (TKA/THA), however there is considerable practice variation regarding its timing, content and duration. This study aims to compare the (cost-) effectiveness of a standardized, treat-to-target postoperative physiotherapy strategy with usual postoperative care. METHODS: Using a cluster randomized study design, consecutive patients scheduled for a primary TKA/THA in 18 hospitals in the Netherlands will be assigned to the treat-to-target physio therapy strategy or usual postoperative care. With the treat-to-target strategy a standardized, individually tailored, exercise program is aimed at the attainment of specific functional milestones. Assessments are done at baseline, 6 weeks and 3, 6, 9 and 12 months follow up. The primary outcome will be the Knee injury / Hip disability and Osteoarthritis Outcome Score - Physical Function Short Form (KOOS-PS / HOOS-PS) at 3 months follow up. Secondary outcomes are the numeric rating scale for pain, the Oxford Knee and Hip Scores, performance-based test and the EuroQol 5D-5L for quality of life. Healthcare use, productivity and satisfaction with postoperative care are measured by means of questionnaires. In total, 624 patients will be needed of which 312 TKA and 312 THA patients. DISCUSSION: The study will provide evidence concerning the (cost-) effectiveness of the treat-to-target postoperative physiotherapy treatment compared to usual postoperative care. The results of this study will address an important evidence gap and will have a significant impact in daily practice of the physio therapist. TRIAL REGISTRATION: Registered in the Dutch Trial Registry on April 15, 2018. Registration number: NTR7129 .

The Extent and Nature of Functional Limitations According to the Health Assessment Questionnaire Disability Index in Patients with Rheumatoid Arthritis and Severe Functional Disability.

BACKGROUND: For a subgroup of people with rheumatoid arthritis (RA) and severe disability, insight into their limitations is crucial for adequate treatment. AIM: To describe the extent and nature of functional limitations in people with RA and severe disability and to explore the associations of the extent of the functional limitations with patient characteristics, disease characteristics, and outcome measures. METHODS: Baseline data of 215 participants in an RCT on the (cost-)effectiveness of longstanding physiotherapy were used. Functional limitations were assessed with the Health Assessment Questionnaire Disability Index (HAQ-DI). The total HAQ-DI including eight domain scores were calculated. Associations between high HAQ-DI scores (≥2, yes/no) and other variables were examined using the Student's t-test or Chi-squared test where appropriate. RESULTS: The participants (90% women, age 58.8 ± 12.8 years) had a mean HAQ-DI score of 1.7 ± 0.5. The majority (56%) showed a moderate-to-severe disability in all domains. Higher HAQ-DI scores seemed to be associated with advanced age, longer disease duration, unemployment, joint replacements, and outcomes for daily functioning and physical quality of life, but not with measures of disease activity. CONCLUSIONS: Our findings indicate that a comprehensive assessment of all areas of daily activities in this subgroup is necessary in order to provide appropriate (non-)pharmacological care.

Postgraduate education to increase adherence to a Dutch physiotherapy practice guideline for hip and knee OA: a randomized controlled trial.

OBJECTIVE: To compare the effectiveness of two educational courses aiming to improve adherence to recommendations in a Dutch physiotherapy practice guideline for hip and knee OA. METHODS: Physiotherapists (PTs) from three regions in The Netherlands were invited to participate in a study comparing an interactive workshop (IW) with conventional education (CE). Participants were randomly assigned to one of the two courses. Satisfaction with the course (scale 0-10), knowledge (score range 0-76) and guideline adherence (score range 0-72) were measured at baseline, immediately after the educational course and 3 months after that. Data were analysed using a linear mixed model. RESULTS: In total, 203 (10%) PTs participated in the IW (n = 108) and the CE (n = 95). There were no differences between groups at baseline. Satisfaction was significantly higher in the IW than in the CE group [mean scores (S.D.) 7.5 (1.1) and 6.7 (1.6), respectively (P < 0.001)]. A significantly greater improvement in adherence was seen over time in the IW group compared with the CE group (F = 3.763, P = 0.024), whereas the difference in improvement of knowledge was not significant (F = 1.283, P = 0.278). CONCLUSION: An IW led to greater satisfaction and was more effective in improving adherence to recommendations in a PT guideline on hip and knee OA than CE, whereas the increase in knowledge did not differ significantly.

Consensus-based recommendations on communication and education regarding primary care physical therapy for patients with systemic sclerosis.

OBJECTIVE: This study aimed to develop recommendations for communication and postgraduate education regarding primary care physical therapy for systemic sclerosis (SSc) patients. METHODS: A virtual Nominal Group Technique was used with tasks forces for communication (n = 18) and education (n = 21). Both included rheumatologists, physical therapists (PTs) in primary, secondary or tertiary care, rheumatology nurses, advanced nurse practictioners and patient representatives. Three online meetings were organised for each task force to discuss (1) current bottlenecks; (2) potential solutions; and (3) the resulting draft recommendations. After the final adjustments, participants rated their level of agreement with each recommendation on a scale from 0 (not at all agree) to 100 (totally agree), using an online questionnaire. RESULTS: 19 and 34 recommendations were formulated for communication and education, respectively. For communication the main recommendations concerned the provision of an overview of primary care physical therapists with expertise in rheumatic and musculoskeletal diseases to patients and rheumatologists, the inclusion of the indication by the rheumatologist in the referral to the physical therapist and low-threshold communication with the rheumatologist in case of questions or concerns of the physical therapist. For postgraduate education three types of "on demand" educational offerings were recommended with varying levels of content and duration, to match the competencies and preferences of individual primary care physical therapists. CONCLUSION: Using a systematic qualitative approach, two multi-stakeholder task forces developed practical recommendations for primary care physical therapists' communication with hospital-based care providers and postgraduate education regarding the treatment of SSc patients.

Educational readiness among health professionals in rheumatology: low awareness of EULAR offerings and unfamiliarity with the course content as major barriers-results of a EULAR-funded European survey.

BACKGROUND: Ongoing education of health professionals in rheumatology (HPR) is critical for high-quality care. An essential factor is education readiness and a high quality of educational offerings. We explored which factors contributed to education readiness and investigated currently offered postgraduate education, including the European Alliance of Associations for Rheumatology (EULAR) offerings. METHODS AND PARTICIPANTS: We developed an online questionnaire, translated it into 24 languages and distributed it in 30 European countries. We used natural language processing and the Latent Dirichlet Allocation to analyse the qualitative experiences of the participants as well as descriptive statistics and multiple logistic regression to determine factors influencing postgraduate educational readiness. Reporting followed the Checklist for Reporting Results of Internet E-Surveys guideline. RESULTS: The questionnaire was accessed 3589 times, and 667 complete responses from 34 European countries were recorded. The highest educational needs were 'professional development', 'prevention and lifestyle intervention'. Older age, more working experience in rheumatology and higher education levels were positively associated with higher postgraduate educational readiness. While more than half of the HPR were familiar with EULAR as an association and the respondents reported an increased interest in the content of the educational offerings, the courses and the annual congress were poorly attended due to a lack of awareness, comparatively high costs and language barriers. CONCLUSIONS: To promote the uptake of EULAR educational offerings, attention is needed to increase awareness among national organisations, offer accessible participation costs, and address language barriers.

Avoidance of activities in early symptomatic knee osteoarthritis: results from the CHECK cohort.

BACKGROUND: Pain-related avoidance of activities is hypothesized to lead to lower muscle strength and thereby activity limitations. Negative affect (e.g., low vitality, depression) is thought to strengthen the tendency to avoid activities. PURPOSE: The aim of this study was to assess the validity of this "avoidance model" in patients with early symptomatic knee osteoarthritis (OA). METHODS: Cross-sectional data (n=151) were used. The associations between pain, negative affect, avoidance, muscle strength, and activity limitations were modeled using structural equation modeling. RESULTS: Pain and negative affect were associated with lower muscle strength via avoidance (mediation by avoidance). Avoidance was associated with activity limitations via lower muscle strength (mediation by muscle strength). There were also direct associations between pain, negative affect, avoidance, muscle strength, and activity limitations. CONCLUSIONS: The results support the validity of the avoidance model, which explains the associations between pain, negative affect, avoidance, muscle strength, and activity limitations in patients with early symptomatic knee OA.

Effectiveness and cost-effectiveness of longstanding exercise therapy versus usual care in patients with axial spondyloarthritis or rheumatoid arthritis and severe limitations: The protocols of two parallel randomized controlled trials.

OBJECTIVES: Research on effectiveness and cost-effectiveness of longstanding exercise therapy in patients with axial SpondyloArthritis (axSpA) or Rheumatoid Arthritis (RA) is scarce, and mainly concerned patients with a relatively favorable health status. We aim to evaluate the effectiveness and cost-effectiveness of longstanding exercise therapy compared to usual care in the subgroup of patients with axSpA or RA and severe limitations in functioning. METHODS: In two separate, parallel randomized controlled trials the effectiveness and cost-effectiveness of longstanding, active exercise therapy (52 weeks) compared with usual care (1:1) will be evaluated. The longstanding, active exercise therapy will focus on improving individual limitations in daily activities and participation and will be given by a trained physical therapist in the vicinity of the participant. For each diagnosis, 215 patients with severe limitations in activities and participation will be included. Assessments are performed at baseline, 12, 26, and 52 weeks. The primary outcome measure of effectiveness is the individual level of functioning (activities and participation), as measured with the Patient-Specific Complaints instrument at 52 weeks. For cost-effectiveness analyses, the EuroQol (EQ-5D-5L) and questionnaires on healthcare use and productivity will be administered. The economic evaluation will be a cost-utility analysis from a societal perspective. After 52 weeks, the patients in the usual care group are offered longstanding, active exercise therapy as well. Follow-up assessments are done at 104, 156, and 208 weeks. CONCLUSION: The results of these studies will provide insights in the effectiveness and cost-effectiveness of longstanding exercise therapy in the subgroup of axSpA and RA patients with severe functional limitations.

Clinical Practice Guideline for Physical Therapist Management of People With Rheumatoid Arthritis.

OBJECTIVE: This guideline revises the 2008 Royal Dutch Society for Physical Therapy guideline for physical therapy for patients with rheumatoid arthritis (RA). METHOD: This revised guideline was developed according to the Appraisal of Guidelines for Research and Evaluation tool and the Guidelines International Network standards. A multidisciplinary guideline panel formulated clinical questions based on perceived barriers in current care. For every clinical question, a narrative or systematic literature review was undertaken, where appropriate. The guideline panel formulated recommendations based on the results of the literature reviews, the values and preferences of patients and clinicians, and the acceptability, feasibility, and costs, as described in the Grading of Recommendations Assessment, Development and Evaluation evidence-to-decision framework. RESULTS: The eventual guideline describes a comprehensive assessment based on the International Classification of Functioning, Disability and Health Core Set for RA. It also includes a description of yellow and red flags to support direct access. Based on the assessment, 3 treatment profiles are distinguished: (1) education and exercise instructions with limited supervision, (2) education and short-term supervised exercise therapy, and (3) education and intensified supervised exercise therapy. Education includes RA-related information, advice, and self-management support. Exercises are based on recommendations concerning the desired frequency, intensity, type, and time-related characteristics of the exercises (FITT factors). Their interpretation is compliant with the individual patient's situation and with public health recommendations for health-enhancing physical activity. Recommended measurement instruments for monitoring and evaluation include the Patient-Specific Complaint instrument, Numeric Rating Scales for pain and fatigue, the Health Assessment Questionnaire Disability Index, and the 6-minute walk test. CONCLUSION: An evidence-based physical therapy guideline was delivered, providing ready-to-use recommendations on the assessment and treatment of patients with RA. An active implementation strategy to enhance its use in daily practice is advised. IMPACT: This evidence-based practice guideline guides the physical therapist in the treatment of patients with RA. The cornerstones of physical therapist treatment for patients with RA are active exercise therapy in combination with education. Passive interventions such as massage, electrotherapy, thermotherapy, low-level laser therapy, ultrasound, and medical taping play a subordinate role.

Cross-cultural validity of the Animated Activity Questionnaire for patients with hip and knee osteoarthritis: a comparison between the Netherlands and Brazil.

BACKGROUND: The Animated Activity Questionnaire (AAQ) was developed in the Netherlands to assess activity limitations in individuals with hip/knee osteoarthritis (HKOA). The AAQ is easy to implement and minimizes the disadvantages of questionnaires and performance-based tests by closely mimicking real-life situations. The AAQ has already been cross-culturally validated in six other countries. OBJECTIVE: To assess the cross-cultural validity, the construct validity, the reliability of the AAQ in a Brazilian sample of individuals with HKOA, and the influence of formal education on the construct validity of the AAQ. METHODS: The Brazilian sample (N = 200), mean age 64.4 years, completed the AAQ and the Western Ontario and McMaster Universities Index (WOMAC). A subgroup of participants performed physical function tests and completed the AAQ twice with a one-week interval. The Dutch sample (N = 279) was included to examine Differential Item Functioning (DIF) between the scores obtained in the Netherlands and Brazil. For this purpose, ordinal regression analyses were used to evaluate whether individuals with the same level of activity limitations from the two countries (the Dutch as the reference group) scored similarly in each AAQ item. To evaluate the construct validity, correlation coefficients were calculated between the AAQ, the WOMAC domains, and the performance-based tests. To evaluate reliability, the Cronbach's alpha coefficient, the intraclass correlation coefficient, and the standard error of measurement (SEM) were calculated. RESULTS: The AAQ showed significant correlations with all the WOMAC domains and performance-based tests (rho=0.46-0.77). The AAQ showed high internal consistency (Cronbach's alpha=0.94), excellent test-retest reliability (ICC2,1 = 0.98), and small SEM (2.25). Comparing to the scores from the Netherlands, the AAQ showed DIF in two items, however, they did not impact on the total AAQ score (rho=0.99). CONCLUSION: Overall, the AAQ showed adequate cross-cultural validity, construct validity, and reliability, which enables its use in Brazil and international/multicenter studies.

A clinical practice guideline for physical therapy in patients with hip or knee osteoarthritis.

OBJECTIVE: The purpose of this paper is to revise the 2010 Dutch guideline for physical therapy (PT) in patients with hip or knee osteoarthritis (OA), issued by the Royal Dutch Society for Physical Therapy (KNGF). METHOD: This revised guideline was developed according to the Appraisal of Guidelines for Research and Evaluation (AGREE) and Guidelines International Network (G-I-N) standards. A multidisciplinary guideline panel formulated clinical questions based on perceived barriers to current care. A narrative or systematic literature review was undertaken in response to each clinical question. The panel formulated recommendations based on evidence and additional considerations, as described in the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Evidence-to-Decision framework. RESULTS: A comprehensive assessment should be based on the International Classification of Functioning Disability and Health (ICF) core set for OA, including the identification of OA-related red flags. Based on the assessment, four treatment profiles were distinguished: (1) education and instructions for unsupervised exercises, (2) education and short-term supervised exercise therapy, (3) education and longer term supervised exercise therapy, and (4) education and exercise therapy before and/or after total hip or knee surgery. Education included individualized information, advice, instructions, and self-management support. Exercise programs were tailored to individual OA-related issues, were adequately dosed, and were in line with public health recommendations for physical activity. Recommended measurement instruments included the Patient-Specific Complaints Instrument, the Numeric Pain Rating Scale, the Hip Disability and Osteoarthritis Outcome Score/the Knee Injury Osteoarthritis Outcome Score, and the Six Minute Walk Test. CONCLUSION: An evidence-based PT guideline for the management of patients with hip or knee OA was developed. To improve quality of care for these patients, an extensive implementation strategy is necessary.

Evaluation of an educational course for primary care physiotherapists on comorbidity-adapted exercise therapy in knee osteoarthritis: an observational study.

OBJECTIVE: The objectives of the present study were to: (1) evaluate the effect of an educational course on competence (knowledge and clinical reasoning) of primary care physical therapists (PTs) in treating patients with knee osteoarthritis (KOA) and comorbidity according to the developed strategy; and (2) identify facilitators and barriers for usage. METHOD: The present research was an observational study with a pretest-posttest design using mixed methods. PTs were offered a postgraduate course consisting of e-learning and two workshops (blended education) on the application of a strategy for exercise prescription in patients with KOA and comorbidity. Competences were measured by questionnaire on knowledge (administered before and 2 weeks after the course), and a patient vignette to measure clinical reasoning (administered before the course and after a 6 month period of treating patients). Facilitators and barriers for using the strategy were assessed by a questionnaire and semi-structured interviews. RESULTS: Thirty-four PTs were included. Competence (knowledge and clinical reasoning) improved significantly (p < 0.01). Fourteen out of 34 PTs had actually treated patients with KOA and comorbidity, during a 6-month period. The strategy was found to be feasible in daily practice. The main barriers included the limited number of (self-) referrals of patients, limited number of reimbursed treatment sessions by insurance companies and a suboptimal collaboration with (referring) physicians. CONCLUSION: A blended course on exercise therapy for patients with KOA and comorbidity seems to improve PTs' competence through increasing knowledge and clinical reasoning skills. Identified barriers should be solved before large-scale implementation of exercise therapy can take place in these complex patients.

Stratified exercise therapy compared with usual care by physical therapists in patients with knee osteoarthritis: A randomized controlled trial protocol (OCTOPuS study).

OBJECTIVES: Knee osteoarthritis (OA) is characterized by its heterogeneity, with large differences in clinical characteristics between patients. Therefore, a stratified approach to exercise therapy, whereby patients are allocated to homogeneous subgroups and receive a stratified, subgroup-specific intervention, can be expected to optimize current clinical effects. Recently, we developed and pilot tested a model of stratified exercise therapy based on clinically relevant subgroups of knee OA patients that we previously identified. Based on the promising results, it is timely to evaluate the (cost-)effectiveness of stratified exercise therapy compared with usual, "nonstratified" exercise therapy. METHODS: A pragmatic cluster randomized controlled trial including economic and process evaluation, comparing stratified exercise therapy with usual care by physical therapists (PTs) in primary care, in a total of 408 patients with clinically diagnosed knee OA. Eligible physical therapy practices are randomized in a 1:2 ratio to provide the experimental (in 204 patients) or control intervention (in 204 patients), respectively. The experimental intervention is a model of stratified exercise therapy consisting of (a) a stratification algorithm that allocates patients to a "high muscle strength subgroup," "low muscle strength subgroup," or "obesity subgroup" and (b) subgroup-specific, protocolized exercise therapy (with an additional dietary intervention from a dietician for the obesity subgroup only). The control intervention will be usual best practice by PTs (i.e., nonstratified exercise therapy). Our primary outcome measures are knee pain severity (Numeric Rating Scale) and physical functioning (Knee Injury and Osteoarthritis Outcome Score subscale daily living). Measurements will be performed at baseline, 3-month (primary endpoint), 6-month (questionnaires only), and 12-month follow-up, with an additional cost questionnaire at 9 months. Intention-to-treat, multilevel, regression analysis comparing stratified versus usual care will be performed. CONCLUSION: This study will demonstrate whether stratified care provided by primary care PTs is effective and cost-effective compared with usual best practice from PTs.

Responsiveness and interpretability of the Animated Activity Questionnaire for assessing activity limitations of patients with hip or knee osteoarthritis.

PURPOSE: The aim of the study was to determine the responsiveness and interpretability of the Animated Activity Questionnaire (AAQ), an online questionnaire in which osteoarthritis patients select animations that best match their performance of daily activities. METHODS: A longitudinal study was carried out, in which 94 patients with hip or knee osteoarthritis were assessed at baseline, and 3 and 6 months after treatment (conservative and surgical). Responsiveness was assessed by means of testing hypotheses about expected correlations between change in AAQ, a Global Rating Scale of change (GRS) and change in the Activities of Daily Living subscale of the Hip disability or Knee injury and Osteoarthritis Outcome Score (H/KOOS), and a combination of performance-based tests (the 30 s chair-stand test, the timed up-and-go test and the nine-step stair climbing test). The minimal important change (MIC) was estimated by means of the receiving operating characteristics (ROC) method. RESULTS: The correlations of the AAQ with the H/KOOS were as expected, but other correlations were lower than anticipated. The area under the ROC curve was 0.74 at 6 months. At 3 months' follow-up, the correlations were too low to calculate a MIC. A total of 20% of the results at 3 months and 80% of the results at 6 months were in accordance with the hypotheses. The MIC was 9 points at 6 months. CONCLUSIONS: The AAQ was sufficiently responsive at the six-months follow-up, but not at the three-month follow-up. The MIC at the 6-month follow-up (9 points) was slightly lower than the smallest detectable change of 14 points found in a previous study.

Cross-Cultural and Construct Validity of the Animated Activity Questionnaire.

OBJECTIVE: The Animated Activity Questionnaire (AAQ) assesses activity limitations in patients with hip/knee osteoarthritis and consists of video animations; the patients choose the animation that best matches their own performance. The AAQ has shown good validity and reliability. This study aims to evaluate cross-cultural and construct validity of the AAQ. METHODS: Cross-cultural validity was assessed using ordinal logistic regression analysis to evaluate differential item functioning (DIF) across 7 languages. Construct validity was assessed by testing correlations between the AAQ and a patient-reported outcome measure (PROM) and performance-based tests. RESULTS: Data from 1,239 patients were available. Compared to the Dutch language (n = 279), none of the 17 items showed DIF in English (n = 202) or French (n = 193), 1 item showed uniform DIF in Spanish (n = 99) and Norwegian (n = 62), and 2 items showed uniform DIF in Danish (n = 201). In all these languages, the occurrence of DIF did not influence the total score, which remained comparable with the original Dutch version. For Italian (n = 203) versus Dutch, however, 6 items showed uniform DIF, and 1 item showed nonuniform DIF, indicating some problems with the cross-cultural validity between these countries. With regard to construct validity, the correlations with PROM (0.74) and performance-based tests (0.36-0.68) were partly as expected (>0.60). CONCLUSION: The AAQ, an innovative tool to measure activity limitations that can be placed on the continuum between PROMs and performance-based tests, showed a good overall cross-cultural validity, and seems to have great potential for international use in research and daily clinical practice in many European countries.